Conventionally, image forming apparatuses equipped with different types of detection functions have been proposed as the image forming apparatuses such as copying machines that acquire image data by reading out the images recorded on the original document and carry out image formation on recording sheets of the images of that image data.
For example, in Patent Document 1, an image forming apparatus has been described that counts the number of successive dots, and detects the residual quantity of toner by summing the toner consumption quantity for each dot.
Further, in Patent Document 2, an image forming apparatus has been described that detects the residual quantity of toner by detecting the print ratio per page and the magnitude of the developing electrical charge.
In addition, in Patent Document 3, an image forming apparatus has been described that sums the number of black dots included in the pages to be printed after replacing the toner cartridge, and detects the extent of use of the toner cartridge from the ratio of this number of dots to the total number of dots that can be printed with one toner cartridge.
Further, in Patent Document 4, an image forming apparatus has been described that has a display section that displays the number of pixels of a particular color or the ratio of that number of pixels to the entire page.
On the other hand, in recent years, there are ever increasing numbers of functions installed in an image forming apparatus, and the large software for realizing these functions has become the cause of generating latent bugs. In addition, in the case of image forming apparatuses delivered to businesses that output as sold products a large number of copies of booklets, the problem of erratic pagination or missing printed pages of books is a serious problem and even bugs in the software can also be causes of erratic pagination or missing printed pages of a book.    [Patent Document 1] JP-A No. 6-138769 (Hereinafter, JP-A refers to Japanese Patent Publication Open to Public Inspection)    [Patent Document 2] JP-A No. 8-044257    [Patent Document 3] JP-A No. 10-105009    [Patent Document 4] JP-A No. 2000-032199
However, in the inventions disclosed in Patent Document 1 to Patent Document 3, all of these inventions are related to detecting the residual quantity of toner using the print ratio, and also, the invention disclosed in Patent Document 4 is related to displaying the print ratio, but none of these inventions was able to detect erratic pagination or missing printed pages of books.